BlackBerry Growing at Same Rate as Android, Globally?

Numbers don’t lie, right? Now, granted, they don’t always tell the full picture, but these numbers from Statcounter seem fairly straightforward. The lines that you see on the above chart are global numbers pulled from the past year.
Apple’s iPhone has taken a bit of a dip after a couple years of relatively astronomical growth. Symbian, still the leader of the global pack, stumbled a bit, briefly overtaken by Apple, but has more or less maintained its position.
As for BlackBery and Android, the second a third place operating systems have both grown pretty steadily over the past twelve months–and at what looks to be roughly the same rate.
Given what appears to be occurring on the hardware sign of things, these numbers seem surprising. Android really appears to be ready to overtake RIM in a big way. Keep in mind, however, that, again, these are global numbers–the US tends to be its own beast when it comes to mobile operating systems.
Symbian? What’s that?